Mickelson putted a moving ball during Saturday’s third round with it set to roll off the green as conditions wreaked havoc with the world’s best players. The veteran American was questioned shortly afterwards and insisted that he was playing within the rules, even calling on those who were offended by his actions ‘to toughen up’.

Mickelson then reportedly offered to withdraw from the only Major championship he hasn’t won but USGA chief Mike Davis did not take him up on that offer, insisting that the committee had correctly assessed a two-stroke penalty.

The golf world was abuzz with criticism over the USGA’s handling of the incident with the 48-year-old still heavily criticised in the fallout from his 13th-green fiasco.

On Wednesday, it was revealed that he had put word out that he was more apologetic than in the immediate aftermath.

‘I know this should’ve come sooner, but it’s taken me a few days to calm down,’ Mickelson texted a select few US journalists.

‘My anger and frustration got the best of me last weekend. I’m embarrassed and disappointed by my actions. It was clearly not my finest moment and I’m sorry.’

In Sunday’s final round, Mickelson made par on the 13th and sarcastically jumped in the air in his trademark Masters winning celebration. After the round, he signed autographs and took pictures before snubbing the waiting media.

‘He’s a good man who had a bad moment,’ said his wife, Amy, on Sunday.

‘He’s not perfect — I’m not, you’re not… You might have a bad day at work or do something or say something that you regret. When [players] do it, it’s on a very large stage and there’s so much immediate reaction on Twitter and social media, it can overwhelm.

‘It was very uncharacteristic. If he acted like that all the time, I think that’s different. I think everyone should be allowed to have a moment.’

Brooks Koepka won the US Open for the second time in succession and finished 15 shots ahead of Mickelson.